1. Field of the Invention
The present invention relates to a single-layer projected capacitive touch panel and a method for manufacturing the same, and more particularly to a single-layer projected capacitive touch panel in which a single glass layer is required, and a method of manufacturing the same.
2. Description of Related Art
The advancement of touch panel technology has resulted in many consumer electronic products such as personal digital assistant (PDA), global positioning systems (GPS) and the like being equipped with touch panels.
Before iPhone™ was released, resistive touch panels were generally used on small size portable electronic devices because they had sufficiently matured to keep costs low and be reliable. However, resistive touch panels cannot track more than one finger so resistive touch panels cannot resolve multipoint touches. After iPhone™ was announced, projected capacitive touch panels became desirable because it enables multipoint touch.
With reference to FIG. 5, a conventional projected capacitive touch panel comprises a glass base (91), a touch sensing circuit layer (92), a conductive wire layer (93), an insulator layer (94), a conductive glue layer (95), a flexible printed circuit (FPC) board (96), an optical glue layer (97) and a glass cover (98). The glass base (91) has a circuit surface (911). The touch sensing circuit layer (92) is composed of single-layer touch sensing circuits, and the touch sensing circuit layer (92) and the conductive wire layer (93) are formed on the circuit surface (911) of the glass base (91) and are electronically connected together. The insulator layer (94) is formed on and covers the conductive wire layer (93), and the insulator layer (94) has a breach to partially expose the conductive wire layer (93). The conductive glue layer (95) is formed on the breach of the insulator layer (94) to cover the exposed conductive wire layer (93). The FPC board (96) is adhered to the conductive glue layer (95) and electronically to the conductive wire layer (93) via the conductive glue layer (95). The optical glue layer (97) is formed on the touch sensing circuit layer (92) and the insulator layer (94). The glass cover (98) has an operating surface (981) and an adhering surface (982). The adhering surface (982) of the glass cover (98) is adhered to the optical glue layer (97). The operating surface (981) of the glass cover (98) functions either as a touch surface or a protection cover to protect the touch sensing circuit layer (92), the conductive wire layer (93) and the conductive glue layer (95) on the glass base (91).
Since the conventional projected capacitive touch panel requires two glasses (91, 98), and the two glasses (91, 98) are fixed by the optical glue layer (97), the conventional projected capacitive touch panel has the disadvantages.
1. The optical glue layer (97) is positioned between the glass base (91) and the glass cover (98) so reduces penetrability of the conventional projected capacitive touch panel.
2. Adhering the two glasses (91, 98) requires great accuracy so affecting manufacturing yield rate. Current techniques cannot provide high accuracy of adhering the glasses for increased yield rate of manufacturing the conventional projected capacitive touch panel.
3. The insulator layer (94) and the FPC board (96) may be visible from the operating surface (981) of the glass cover (98) because the optical glue layer (97) is transparent. When installing the conventional projected capacitive touch panel on an electronic device, a casing on the electronic device must be designed to have opaque rims to cover the insulator layer (94) and the FPC board (96). However, such design limitation restricts application and in also requires accurate machining so further raising costs and reducing manufacturing yield.
To overcome the shortcomings, the present invention provides a single-layer projected capacitive touch panel and a method of manufacturing the same to mitigate or obviate the aforementioned problems.